Stoichiometry and point defects in lithium niobate crystals

1983 ◽  
Vol 18 (9) ◽  
pp. 1147-1149 ◽  
Author(s):  
W. Bollmann
Keyword(s):  
Lithium Niobate ◽  
Point Defects ◽  
Lithium Niobate Crystals

scholarly journals CALCULATION OF THE POINT DEFECT CONCENTRATION OF THE CATION SUBLATTICE AND HYDROXYL GROUPS IN LITHIUM NIOBATE CRYSTALS OF DIFFERENT COMPOSITION

2020 ◽  
pp. 200-205
Author(s):  
Наталья Александровна Теплякова ◽  
Николай Васильевич Сидоров ◽  
Михаил Николаевич Палатников
Keyword(s):  
Phase Diagram ◽  
Lithium Niobate ◽  
Point Defects ◽  
Cation Sublattice ◽  
Hydroxyl Groups ◽  
Ir Absorption ◽  
Oh Groups ◽  
Ir Absorption Spectra ◽  
Stretching Vibrations ◽  
Lithium Niobate Crystals

Исследованы ИК-спектры поглощения в области валентных колебаний OH - групп кристаллов ниобата лития стехиометрического и конгруэнтного составов. Рассчитана концентрация OH - групп, отношение Li / Nb, а также концентрация точечных дефектов Nb и V. Результаты расчетов совпадают с литературными данными и подтверждаются фазовой диаграммой ниобата лития. Показано, что увеличение количества свободных протонов (вносящих вклад в проводимость) может обуславливать более высокие электропроводность, скорость термической фиксации голограмм и снижение эффекта фоторефракции. The IR absorption spectra in the region of stretching vibrations of OH - groups of lithium niobate crystals of stoichiometric and congruent compositions are studied. The results of calculations of the OH - groups concentration, the Li / Nb ratio and the concentration of point defects Nb and V coincide with the literature data. The phase diagram of lithium niobate confirms these results. It is shown that an increase in the number of free protons that contribute to conductivity can lead to reducing the optical damage and higher electrical conductivity and the rate of thermal fixation of holograms.

scholarly journals Фотолюминесценция и особенности дефектной структуры конгруэнтных и близких к стехиометрическому составу кристаллов ниобата лития, полученных по разным технологиям

2020 ◽  
Vol 128 (5) ◽  
pp. 643
Author(s):  
Н.В. Сидоров ◽  
М.В. Смирнов ◽  
Н.А. Теплякова ◽  
М.Н. Палатников
Keyword(s):  
Lithium Niobate ◽  
Point Defects ◽  
Luminescence Intensity ◽  
Oh Groups ◽  
Lithium Niobate Crystals

Photoluminescence was studied in the volume of congruent and near-stoichiometric lithium niobate crystals obtained by different technologies. Luminescence intensity in near-stoichiometric crystals was found to be lower than that in a congruent crystal. We have shown that not only basic centers (caused by point defects NbLi, VLi) contribute to luminescence, but also complex defects caused by existence of OH-groups.

Growth and Characterization of High Homogeneity Heavily MgO-doped Lithium Niobate Crystals

2011 ◽  
Vol 25 (12) ◽  
pp. 1257-1262 ◽  
Author(s):  
Xiao-Niu TU ◽  
Yan-Qing ZHENG ◽  
Hui CHEN ◽  
Hai-Kuan KONG ◽  
Jun XIN ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
High Homogeneity ◽  
Lithium Niobate Crystals

Formation of Regular Domain Structures in Quenched Ferroelectrics Under the Influence of an External High-frequency Electric Field

2019 ◽  
Vol 9 (3) ◽  
pp. 344-352 ◽  
Author(s):  
L.I. Stefanovich ◽  
O.Y. Mazur ◽  
V.V. Sobolev
Keyword(s):  
Lithium Niobate ◽  
Electric Field ◽  
Domain Structure ◽  
High Frequency ◽  
Evolution Equations ◽  
Regular Domain ◽  
Field Frequency ◽  
Domain Structures ◽  
Alternating Electric Field ◽  
Lithium Niobate Crystals

Introduction: Within the framework of the phenomenological theory of phase transitions of the second kind of Ginzburg-Landau, the kinetics of ordering of a rapidly quenched highly nonequilibrium domain structure is considered using the lithium tantalate and lithium niobate crystals as an example. Experimental: Using the statistical approach, evolution equations describing the formation of the domain structure under the influence of a high-frequency alternating electric field in the form of a standing wave were obtained. Numerical analysis has shown the possibility of forming thermodynamically stable mono- and polydomain structures. It turned out that the process of relaxation of the system to the state of thermodynamic equilibrium can proceed directly or with the formation of intermediate quasi-stationary polydomain asymmetric phases. Results: It is shown that the formation of Regular Domain Structures (RDS) is of a threshold character and occurs under the influence of an alternating electric field with an amplitude less than the critical value, whose value depends on the field frequency. The conditions for the formation of RDSs with a micrometer spatial scale were determined. Conclusion: As shown by numerical studies, the RDSs obtained retain their stability, i.e. do not disappear even after turning off the external electric field. Qualitative analysis using lithium niobate crystals as an example has shown the possibility of RDSs formation in high-frequency fields with small amplitude under resonance conditions

scholarly journals Boron Influence on Defect Structure and Properties of Lithium Niobate Crystals

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 458
Author(s):  
Nikolay V. Sidorov ◽  
Natalia A. Teplyakova ◽  
Olga V. Makarova ◽  
Mikhail N. Palatnikov ◽  
Roman A. Titov ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Defect Structure ◽  
Photorefractive Effect ◽  
Ferroelectric Properties ◽  
High Concentration ◽  
Oh Groups ◽  
Boron Doped ◽  
Compositional Uniformity ◽  
Boron Dopant ◽  
Lithium Niobate Crystals

Defect structure of nominally pure lithium niobate crystals grown from a boron doped charge have been studied by Raman and optical spectroscopy, laser conoscopy, and photoinduced light scattering. An influence of boron dopant on optical uniformity, photoelectrical fields values, and band gap have been also studied by these methods in LiNbO3 crystals. Despite a high concentration of boron in the charge (up to 2 mol%), content in the crystal does not exceed 10−4 wt%. We have calculated that boron incorporates only into tetrahedral voids of crystal structure as a part of groups [BO3]3−, which changes O–O bonds lengths in O6 octahedra. At this oxygen–metal clusters MeO6 (Me: Li, Nb) change their polarizability. The clusters determine optically nonlinear and ferroelectric properties of a crystal. Chemical interactions in the system Li2O–Nb2O5–B2O3 have been considered. Boron, being an active element, structures lithium niobate melt, which significantly influences defect structure and physical properties of a crystal grown from such a melt. At the same time, amount of defects NbLi and concentration of OH groups in LiNbO3:B is close to that in stoichiometric crystals; photorefractive effect, optical, and compositional uniformity on the contrary is higher.

Microindentation of proton exchange layers on X cut of lithium niobate crystals

2012 ◽  
Vol 135 (2-3) ◽  
pp. 493-496 ◽  
Author(s):  
I.V. Petukhov ◽  
V.I. Kichigin ◽  
A.P. Skachkov ◽  
S.S. Mushinsky ◽  
D.I. Shevtsov ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Proton Exchange ◽  
Lithium Niobate Crystals

scholarly journals Upconversion of Broadband Infrared Radiation into Visible Light for Different Pumping Parameters

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Man Nen Litvinova ◽  
Victor Krishtop ◽  
Evgeniy Tolstov ◽  
Vladimir Troilin ◽  
Larisa Alekseeva ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Visible Light ◽  
Light Beam ◽  
Infrared Radiation ◽  
Spectral Width ◽  
Uniaxial Crystal ◽  
Phase Matching ◽  
Pump Radiation ◽  
Broadband Radiation ◽  
Lithium Niobate Crystals

The influence of pump radiation parameters such as the polarization and the spectral width of infrared radiation on the conversion of broadband radiation in lithium niobate crystals was investigated. The spectra of converted radiation were calculated for two types of phase matching in the negative uniaxial crystal by taking into account the convergence of the light beam in the crystal. Experimental spectra were obtained and compared with the calculated spectra.

Light-mediated ferroelectric domain engineering and micro-structuring of lithium niobate crystals

2011 ◽  
Vol 6 (4) ◽  
pp. 526-548 ◽  
Author(s):  
C.Y.J. Ying ◽  
A.C. Muir ◽  
C.E. Valdivia ◽  
H. Steigerwald ◽  
C.L. Sones ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Ferroelectric Domain ◽  
Domain Engineering ◽  
Micro Structuring ◽  
Lithium Niobate Crystals
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